Shelf



FIG. 1 is a top perspective view of a shelf showing my new design, the horizontal member being shown broken-away to indicate indeterminate length;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a side elevational view thereof; the opposite side elevational view being the mirror image of the view shown; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a shelf, as shown and described. 